福建省2021年福州市七年级第二学期期末数学抽测试卷及答案

所以这个方程组的解是
x
y
1， 1．·····················································································8
分
19．（本小题满分 8 分）
解：解不等式①，得 x≤4．.·······························································································3 分
解不等式②，得 x＞2， ·······························································································6 分
∴不等式组的解集为 2＜x≤4． ·····················································································8 分
③ D A；··················································································································6 分
④内错角相等，两直线平行． ·····························································································8 分
12．4
13．全面调查
14．105°
15．10
16．4≤n＜5
三、解答题：共 9 小题，满分 86 分，请在答题卡的相应位置作答．
17．（本小题满分 8 分）பைடு நூலகம்
解：原式 ( 2 1) 2 (2) ·······························································································6 分
2 1 2 2 ····································································································7 分
2 1． ··········································································································8 分 18．（本小题满分 8 分）
20．（本小题满分 8 分）
①同旁内角互补，两直线平行； ··························································································2 分
②两直线平行，同位角相等； ·····························································································4 分
21．（本小题满分 8 分）
解：依题意，剪掉的每个正方形边长为 25 5 cm，································································1 分 即无盖长方体容器的高为 5 cm． 设原正方形的边长为 x cm． ·························································································2 分 ∵无盖长方体容器的底面是正方形， ∴底面正方形边长为 (x 2 5) (x 10) cm．
(3,0)
P
1/5
2/5
3/5
4/5
5/5
2020—2021 学年度福州市七年级下学期期末质量检测
数学试题答案及评分参考
评分说明： 1．本解答给出了一种或几种解法供参考，如果考生的解法与本解答不同，可根据试题的主要考 查内容比照评分参考制定相应的评分细则． 2．对于计算题，当考生的解答在某一步出现错误时，如果后继部分的解答未改变该题的内容和 难度，可视影响的程度决定后继部分的给分，但不得超过该部分正确解答应给分数的一半； 如果后继部分的解答有较严重的错误，就不再给分． 3．解答右端所注分数，表示考生正确做到这一步应得的累加分数． 4．只给整数分数．选择题和填空题不给中间分．
一、选择题：共 10 小题，每小题 4 分，满分 40 分；在每小题给出的四个选项中，只有一项是符合题目要求的， 请在答题卡的相应位置填涂．
1．A
2．A
3．A
4．B
5． B
6．C
7．D
8．A
9．C
10．B
二、填空题：共 6 小题，每小题 4 分，满分 24 分，请在答题卡的相应位置作答．
11．x＞ 1
解：由①，得 x y 2 ．③ ································································································2 分
把③代入②，得 2( y 2) 3y 1． ··············································································3 分 解这个方程，得 y 1 ． ·····························································································5 分 把 y 1 代入③，得 x 1 ．··························································································7 分